/// <summary>
/// This method aims to discover the value of a tile by a process of elimination.
/// The idea is to look at the plot, and see, if there is only a single tile, where
/// a given value can be placed.
/// </summary>
/// <param name="plotIndex">index of the plot.</param>
/// <returns></returns>
private bool PlotEliminationCheck(int plotIndex)
{
TilePlot currentPlot = this.grid.Plots[plotIndex];
if (currentPlot.IsFull())
{
return(false);
}
bool returnable = false;
for (int i = 1; i <= StandardSize; i++)
{
if (currentPlot.IsDigitConfirmed(i))
{
continue;
}
Tile correctNumberTile = null;
int possibilities = 0;
for (int j = 0; j < StandardSize; j++)
{
Tile currentTile = currentPlot.Tiles[j];
if (currentTile.IsValueSet())
{
continue;
}
if (currentTile.IsDigitPossible(i))
{
correctNumberTile = currentTile;
possibilities++;
}
}
if (possibilities == 1)
{
correctNumberTile.Value = i;
returnable = true;
}
}
return(returnable);
}
/// <summary>
/// This method checks off all the known values in a plot for a given tile.
/// </summary>
/// <param name="plotIndex">Index of the plot.</param>
/// <param name="tileIndex">index of the tile.</param>
private void PlotCheck(int plotIndex, int tileIndex)
{
TilePlot currentPlot = this.grid.Plots[plotIndex];
Tile currentTile = currentPlot.Tiles[tileIndex];
if (currentTile.IsValueSet())
{
return;
}
for (int i = 0; i < StandardSize; i++)
{
Tile tileOfinterest = currentPlot.Tiles[i];
if (tileOfinterest.IsValueSet())
{
currentTile.CrossOffDigit(tileOfinterest.Value);
}
}
}
